Abstract: Disclosed is a method of recovering gold from an aqueous solution having a gold concentration of 10 mg/L or lower, using a plurality of extraction apparatuses for bringing the aqueous solution into contact with an extraction agent, arranged to configure a multi-stage extraction process, the method allowing the aqueous solution to continuously flow from the first-stage extraction process to the next-stage extraction process, while recycling the extraction medium used in each stage twice or more times for the extraction process of the same stage, without back extraction and reduction.

Abstract: This invention relates to a process for the recovery of precious metal/s from a precious metal-containing material in an aqueous leach slurry or solution. The process includes the step of contacting the precious metal/s in the leach slurry or solution with a ligand selected from dithiooxamide (rubeanic acid), or a substituted dithiooxamide. The leaching of PGMs, gold and silver from their ores using the ligand of the present invention may take place under aqueous alkaline conditions, avoiding both corrosive acidic conditions and the use of cyanide.

Abstract: The present invention is directed to flotation of refractory gold sulfide ores and to pressure oxidized residue neutralization using flotation tailings that have been contacted with an off gas of pressure oxidation.

Abstract: The present invention is directed to a precious metal recovery process in which carbonaceous material, such as preg robbing carbon, is floated after sulfide oxidation to separate the carbonaceous material from the precious metal.

Abstract: Disclosed is a method of leaching copper and gold from sulfide ores, which includes Process (1) of bringing a first aqueous acidic solution which contains chlorine ion, copper ion and iron ion, but no bromine ion, into contact with sulfide ores under supply of an oxidizing agent, so as to leach copper component contained in the sulfide ores; Process (2) of separating, by solid-liquid separation, a leaching reaction liquid obtained in Process (1), into a leaching residue and a leachate; and Process (3) of bringing a second aqueous acidic solution which contains chlorine ion, bromine ion, copper ion and iron ion, into contact with the leaching residue obtained in Process (2) under supply of an oxidizing agent, so as to leach gold contained in the leaching residue.

Abstract: The present invention is directed to a precious metal recovery process in which basic ferric sulphates and/or jarosites are controlled by hot curing of the autoclave discharge slurry followed by decomposition of argentojarosite using strong acid consumers.

Abstract: A method and system are provided in which a gold and/or silver-collecting resin-in-leach circuit comprises both co-current and counter-current sections.

Abstract: A method for recovering catalytic elements from a fuel cell membrane electrode assembly is provided. The method includes converting the membrane electrode assembly into a particulate material, wetting the particulate material, forming a slurry comprising the wetted particulate material and an acid leachate adapted to dissolve at least one of the catalytic elements into a soluble catalytic element salt, separating the slurry into a depleted particulate material and a supernatant containing the catalytic element salt, and washing the depleted particulate material to remove any catalytic element salt retained within pores in the depleted particulate material.

Abstract: The present invention provides a method of recovering silver safely and efficiently from a chloride or bromide bath containing various metals. Specifically, a method of recovering silver from a hydrochloric acid solution containing alkali and/or alkaline earth metal chloride, silver, copper and iron ions, comprising the steps of: (1) bringing the solution into contact with a strong-base anion-exchange resin to adsorb silver, copper, and iron on the anion-exchange resin; (2) then washing the anion-exchange resin with water to remove the adsorbed copper and iron; and (3) then bringing the ion-exchange resin into contact with a hydrochloric acid solution to elute the adsorbed silver, is provided.

Abstract: A method for leaching one or more target metals from a sulfide ore and/or concentrate containing such, the method comprising the steps of: (a) Exposing the ore and/or concentrate to an aqueous solution of chlorine-based oxidising species in which the hypochlorous acid comprises at least 10 mol % of the chlorine-based oxidising species; (b) Allowing and/or facilitating the oxidation of the target metals by the hypochlorous acid, thereby decreasing the pH such that the predominant chlorine-based oxidising species becomes chlorine; (c) Allowing and/or facilitating the oxidation of the target metals by the chlorine; (d) Allowing and/or facilitating the dissolution of the target metals by the solution species formed during the oxidation by hypochlorous acid and/or chlorine; and (e) Passing the pregnant solution produced thereby to a means for metal recovery.

Abstract: An improved method for recovering refractory gold from a material comprising treating the material to at least partially remove nitric acid-insoluble lead moieties.

Abstract: A method is disclosed for recovering precious metals from source materials containing precious metals which involves leaching the source material in aqueous reducing liquor to provide a treated solid residue and processing the treated residue to recover precious metals.

Abstract: The present invention relates generally to a process for controlled leaching and sequential recovery of two or more metals from metal-bearing materials. In one exemplary embodiment, recovery of metals from a leached metal-bearing material is controlled and improved by providing a high grade pregnant leach solution (“HGPLS”) and a low grade pregnant leach solution (“LGPLS”) to a single solution extraction plant comprising at least two solution extractor units, at least two stripping units, and, optionally, at least one wash stage.

Abstract: Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ heap leaching or lixiviants that include one or more blinding agents.

Abstract: A process for recovering copper from heap leach residues, the process comprising treating heap leach residues to provide treated heap leach residues providing improved permeability of a heap of the treated heap leach residues, and leaching the heap of the treated heap leach residues with a leaching solution. Treating the heap leach residues includes: a) blending the heap leach residues with additional material to provide a blend; or b) agglomerating the heap leach residues; or c) both blending the heap leach residues with additional material and agglomerating.

Abstract: The present invention is directed to a multi-compartment autoclave using inter-compartment dividers having one or more underflow openings for passing a feed stream between compartments.

Abstract: A method is provided for recovering rhenium from a titania-supported, rhenium-containing catalyst by treating the catalyst in the reduced form with an acid in an amount and for a time sufficient to dissolve the rhenium without dissolving the support.

Abstract: Disclosed herein is a method for concentrating gold contained in a leach residue obtained in a copper hydrometallurgical process for recovering copper from a copper sulfide mineral to efficiently separate and recover gold from the leach residue: a gold-bearing copper sulfide mineral is subjected to pressure leaching with sulfuric acid at a temperature higher than 102° C. and 112° C. or lower to obtain a leach residue, and the leach residue is subjected to flotation to separate it into a float fraction and a sink fraction; the float fraction obtained by flotation is desulfurized to obtain a desulfurized product; the desulfurized product is subjected to oxidative roasting to obtain an oxidatively-roasted product; the oxidatively-roasted product is dissolved in a sulfuric acid solution to obtain a copper solution, and a gold-bearing residue is separated and recovered from the copper solution.

Abstract: A gold thiosulfate leaching process uses carbon to remove gold from the leach liquor. The activated carbon is pretreated with copper cyanide. A copper (on the carbon) to gold (in solution) ratio of at least 1.5 optimizes gold recovery from solution. To recover the gold from the carbon, conventional elution technology works but is dependent on the copper to gold ratio on the carbon.

Abstract: To provide a compound represented by General Formula (1) below, where R denotes a C1-C10 hydrocarbon group, Z denotes any one of a sulfide group, a sulfinyl group and a sulfonyl group, and n denotes an integer of 4 to 8.

Abstract: A method for recovering metal values from refractory sulfide ores is provided. The method includes the steps of separating clays and fines from crushed refractory sulfide ore, forming a heap from the refractory sulfide ore, producing a concentrate of refractory sulfide minerals from the separated fines and adding the concentrate to the heap, bioleaching the heap to thereby oxidize iron sulfides contained therein, and hydrometallurgically treating the bioleached ore to recover metal values contained therein.

Abstract: A method of biotreating and recovering metal values from metal-bearing refractrory sulfide ore using a nonstirred surface bioreactor is provided. According to the method, the surface of a plurality of coarse substrates is coated with a solid material to be biotreated to form a plurality of coated coarse substrates. The coarse substrates have a particle size greater than about 0.3 cm and the solid material to be biotreated has a particle size less than about 250 ?m. A nonstirred surface reactor is then formed by stacking the plurality of coated coarse substrates into a heap or placing the plurality of coated coarse substrates into a tank so that the void volume of the reactor is greater than or equal to about 25%. The solid material is biotreated in the surface bioreactor until the undesired compound in the solid material is degraded to a desired concentration.

Abstract: A process for the extraction of a precious metal, such as gold or silver, from a sulphide ore or concentrate or other source material comprises subjecting the source material to pressure oxidation to produce a pressure oxidation slurry. The pressure oxidation slurry is flashed down to a lower temperature and pressure and is then subjected to a liquid/solid separation to obtain a pressure oxidation solution and a solid residue containing the precious metal. The solid residue is then subjected to cyanidation to extract the precious metal. The formation of thiocyanide during cyanidation is minimized or counteracted by effecting the cyanidation at an elevated oxygen pressure and a reduced retention time, such as 30 to 90 minutes. A method for the reduction of copper cyanide formation during cyanidation leaching is also provided.

Abstract: The present invention relates to a method of recovering rhenium (Re) and other metals from Re-bearing materials.

Abstract: A system and method are disclosed for improving component extraction from heap leach operations. Following heap leaching for some time, portions of the heap deficient in component extraction are identified, and treatment wells are drilled and remedial treatments are selectively performed on the identified portions of the heap. The remedial treatment can include hydraulically fracturing the identified portions of the heap followed by selective treatment with leach solution of the area impacted by the fracturing.

Abstract: A process for extracting gold from a gold-bearing ore. The process includes, first, providing a leaching liquor with thiosulfate anion and ethylenediamine. Next, the leaching liquor is contacted with the gold-bearing ore to form a pregnant leach solution including gold dissolved from the gold-bearing ore. Finally, at least part of the gold in the pregnant leach solution is recovered.

Abstract: An improved process and composition for the extraction of metal from a metal-laden ore, soil or rock is provided. A liquid, three-component aqueous lixiviant comprises water, an alkali metal salt and a low pH acidic composition. A four-component aqueous lixiviant comprises water, a low pH acidic composition, an alkali metal salt and an acid having a pH value less than 2. Both lixiviant compositions are efficient for extracting metal into a pregnant liquid solution. The pregnant solution is treated by known conventional means, such as filtration, centrifuging or electrolysis to remove the extracted metals. The three-component and four-component aqueous lixiviants of the present invention are non-toxic, meaning, not an irritant or deleterious to humans or the environment and perform, as well as, or better than known toxic cyanide lixiviants.

Abstract: Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.

Abstract: Mineral materials comprising copper and precious metal are subjected to an acidic leach of the copper followed by an acidic thiocyanate leach of the precious metal.

Abstract: Process for removing the noble metal from noble metal-containing moulded catalyst bodies, comprising these steps of A leaching the noble metal from loosely heaped moulded catalyst bodies, B removing the mother liquor, C automated conveying of the moulded bodies into a centrifuge, D renewed leaching, E separating off of the residual mother liquor by centrifuging.

Abstract: A method for suppressing mercury dissolution during pressure oxidation of precious metal-containing materials in the presence of halogens and halides is provided. Pressure oxidation is performed under controlled oxidative conditions to maintain the mercury predominantly in the solid residue.

Abstract: A process for recovering metals involving ion exchange comprising the step of recovering metal species from an ion exchange resin by elution of the resin with an eluent system containing (i) a first sulphite component comprising at least one of sulphite and bisulphite ion; and (ii) a second eluting component comprising any species which favours the ion exchange or desorption of a metal species from the resin during elution wherein the presence of the sulphite component (i) increases metal elution efficiency relative to the situation where an eluent comprises the second eluting component alone.

Abstract: A process for recovering a precious metal from a sulfidic material comprises the steps of preparing an acidic aqueous halide solution having an oxidation potential sufficient to oxidize the sulfidic material and render the precious metal soluble in the solution, adding the material to the acidic aqueous halide solution so that the sulfidic material is oxidized and the precious metal is solubilized and separating the precious metal from the oxidized sulfidic material. In addition, a process for removing a contaminant from a contaminated sulfidic material comprises the steps of mixing the material in an aqueous solution wherein a multi-valent species of a relatively high oxidation state oxidizes the contaminant to render it soluble in the solution, produces a contaminant refined material, and is reduced to a relatively lower oxidation state; and removing the contaminant from the solution while regenerating the multi-valent species to its relatively high oxidation state.

Abstract: This invention relates to a method of removing cyanide in the form of free cyanide (cyanide ions i.e. CN?) and weak acid dissociable cyanide (WAD) from an aqueous stream. WAD is cyanide complexed with metals such as Cu. The method finds particular application in removing cyanide from a tail stream from a carbon in leach (CIL) mining operation. The method of the invention is carried out by contacting an aqueous stream containing cyanide with carbon, under conditions wherein the Eh (oxygen reduction potential (ORP) measured in mV) of the aqueous stream is O or above. Advantageously the pH of the solution is buffered to from 7-9.

Abstract: The invention publishes a process to increase the bioleaching speed of ores or concentrates of sulfide metal species in heaps, tailing dams, dumps, or other on-site operations. The process is characterized by the continuous inoculation of the ores or concentrates with isolated microorganisms of the Acidithiobacillus thiooxidans type, together with isolated microorganisms of the Acidithiobacillus ferrooxidans type, with or without native microorganisms, in such a way that the total concentration of microorganisms in the continuous inoculation flow is of around 1×107 cells/ml to 5,6×107 cells/ml. In particular, the invention publishes the continuous inoculation of Acidithiobacillus thiooxidans Licanantay DSM 17318 together with Acidithiobacillus ferrooxidans Wenelen DSM 16786 microorganisms, or with other native microorganisms at a concentration higher than 5×107 cells/ml.

Abstract: A method for recovering catalytic elements from a fuel cell membrane electrode assembly is provided. The method includes converting the membrane electrode assembly into a particulate material, wetting the particulate material, forming a slurry comprising the wetted particulate material and an acid leachate adapted to dissolve at least one of the catalytic elements into a soluble catalytic element salt, separating the slurry into a depleted particulate material and a supernatant containing the catalytic element salt, and washing the depleted particulate material to remove any catalytic element salt retained within pores in the depleted particulate material.

Abstract: A method for selectively recovering a metal from mined ore and other metal-bearing raw source materials is disclosed.

Abstract: Disclosed herein is a method for concentrating gold contained in a leach residue obtained in a copper hydrometallurgical process for recovering copper from a copper sulfide mineral to efficiently separate and recover gold from the leach residue. According to the method, a gold-bearing copper sulfide mineral is subjected to pressure leaching with sulfuric acid at a temperature higher than 102° C. and 112° C. or lower to obtain a leach residue, and the leach residue is subjected to flotation to separate it into a float fraction and a sink fraction. The float fraction obtained by flotation is desulfurized by heating at a temperature of 250 to 800° C. under an inert atmosphere to obtain a desulfurized product. The desulfurized product is subjected to oxidative roasting by heating at a temperature of 600 to 800° C. under an atmosphere of flowing oxygen or air to obtain an oxidatively-roasted product.

Abstract: The invention relates to a method for recovering gold in connection with the hydrometallurgical production of copper from a waste or intermediate product containing sulphur and iron that is generated in the leaching of the copper raw material. The recovery of both copper and gold occurs in a chloride environment. The gold contained in the waste or intermediate is leached by means of divalent copper, oxygen and alkali bromide in a solution of copper (II) chloride and alkali chloride, in conditions where the oxygen-reduction potential is a maximum of 650 mV and the pH a minimum of 0.5. The bromide accelerates the dissolution of the gold.

Abstract: Methods and systems for removing copper minerals from a molybdenite concentrate. One embodiment provides leaching copper from the molybdenite concentrate with a leaching solution comprising ferric chloride, removing molybdenite from the leaching solution, introducing an acid into the leaching solution and introducing O2, O3, or a combination of both, into the leaching solution. A method for regenerating ferric chloride in a leaching solution is also provided. One embodiment provides adding a leaching solution comprising Fe(II) ions, Fe(III) ions, or a combination of both, to a mixture of mineral sulfides, introducing an acid into the leaching solution, and introducing O2, O3, or a combination of both, into the leaching solution.

Abstract: The invention relates to a method for recovering gold from a sulphidic concentrate, particularly one containing arsenopyrite and/or pyrite, hydro-metallurgically. The concentrate is first subjected to leaching with a concentrated solution of alkali chloride and copper (II) chloride, by means of which the copper minerals and some of the gold in the concentrate are made to dissolve. Elemental sulphur and precipitated iron and arsenic compounds are separated from the leaching residue using physical separation methods, whereby the first intermediate is obtained, which contains gold-bearing sulphide minerals and gangue minerals as well as the gold that remains undissolved. The free gold that remains undissolved is separated by means of gravity separation methods. After gravity separation, additional comminution is carried out, after which the sulphide minerals are decomposed and the gold-containing solution or residue is routed to the concentrate leaching circuit.

Abstract: The invention relates to a method for the recovery of gold in connection with the hydrometallurgical production of copper from a residue or intermediate product containing sulphur and iron generated in the leaching of copper raw material. The recovery of both copper and gold takes place in a chloride milieu. The gold contained in the residue or intermediate product is leached using bivalent copper and oxygen in copper (II) chloride-sodium chloride solution in the conditions, where the oxidation-reduction potential is a maximum of 650 mV and the pH at least 1. The iron and sulphur contained in the residue remain for the most part undissolved.

Abstract: A method for recovering metal values from refractory sulfide ores is provided. The method includes the steps of separating clays and fines from crushed refractory sulfide ore, forming a heap from the refractory sulfide ore, producing a concentrate of refractory sulfide minerals from the separated fines and adding the concentrate to the heap, bioleaching the heap to thereby oxidize iron sulfides contained therein, and hydrometallurgically treating the bioleached ore to recover metal values contained therein.

Abstract: The present invention relates to a method for recovering rhenium from an ethylene oxide catalyst containing rhenium and at least silver on a solid support, wherein at least a substantial portion of the rhenium present in the catalyst is extracted by intimate contact of the catalyst with one or more polar non-acidic organic solvents substantially free of water such that a rhenium-containing solution is formed containing the polar non-acidic organic solvent and extracted rhenium, the polar non-acidic organic solvent containing one or more oxygen, nitrogen, and/or halogen atoms in its molecular structure.

Abstract: A method of separating rhodium from platinum and/or palladium includes; chloridizing a raw material including rhodium and at least platinum and/or palladium in chlorine atmosphere and obtaining a soluble salt of platinum and/or palladium; water-leaching chloridized material and dissolving platinum and/or palladium into a solution; filtering the solution; and leaving rhodium in a filtered residue of the solution.

Abstract: A method for manufacturing metal nanoparticles, the method including forming a mixture by dissociating a metallic salt of a metal selected from the group consisting of Ag, Pd, Pt, Au and an alloy thereof as a metal precursor in fatty acid; and adding a metallic salt of a metal selected from the group consisting of Sn(NO3)2, Sn(CH3CO2)2, and Sn(acac)2 as a metallic catalyst into the mixture and mixing the mixture and the metallic salt. According to the method, metal nanoparticles have a uniform particle size distribution and a high yield by performing in a non-aqueous environment without using any organic solvent, and are environmentally friendly due to no use of a reducing agent.

Abstract: Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.

Abstract: A process for extracting gold from a gold-bearing ore. The process includes, first, providing a leaching liquor with thiosulfate anion and ethylenediamine. Next, the leaching liquor is contacted with the gold-bearing ore to form a pregnant leach solution including gold dissolved from the gold-bearing ore. Finally, at least part of the gold in the pregnant leach solution is recovered.

Abstract: A system and method for leaching a metal from a base mineral rock includes a closed reactor vessel into which a slurry containing the ground base mineral rock is fed. The interior space of the vessel is then pressurized via an oxygen supply to a pressure P. The slurry is then agitated under pressure P and within the closed reactor vessel for a time “t”. A blower or compressor re-circulates the oxygen through the slurry. The required pressure P and time “t” are effective for obtaining a metal recovery of up to 98% of the total metal available in the base mineral rock. Tests demonstrate that a time “t” in a range of 8 to 14 minutes and a pressure P of 10 to 50 psi is effective for obtaining the desired recovery amount, depending on the concentration of attacking agent used.

Abstract: The present invention provides a method of recovering silver safely and efficiently from a chloride or bromide bath containing various metals. Specifically, a method of recovering silver from a hydrochloric acid solution containing alkali and/or alkali earth metal chloride, silver; copper and iron ions, comprising the steps of: (1) bringing the solution into contact with a strong-base anion-exchange resin to adsorb silver; copper, and iron on the anion-exchange resin; (2) then washing the anion-exchange resin with water to remove the adsorbed copper and iron; and (3) then bringing the ion-exchange resin into contact with a hydrochloric acid solution to elute the adsorbed silver, is provided.